Isolation and Molecular Identification of Respiratory Diseases Viruses in Poultry During 2020

Abstract Poultry production has affected by multiple respiratory disease triggering serious economic losses in Egypt. In this study, the situation and genetic evolution of respiratory disease in Egypt during 2020 were studied. We collected 53 samples from infected flocks suffered from respiratory signs and variable mortality rate from nine governorates in Egypt during 2020. The collected samples were examined for detection of respiratory disease viruses (Avian influenza virus (AIV), Infectious bronchitis virus (IBV), and Newcastle disease virus (NDV)) by rRT-PCR. The single infection was confirmed in 90.6% (37.7% I. B, 30.2% AIV (H5N8), 9.4% I. B and 5.7% NDV) and co-infection of HPAIV (H5N8) + I.BV and LPAIV (H9N2) +IBV were detected in 3.8% in nine governorates. The HA gene of HPAIV (H5N8) were cluster to clad 2.3.4.4.1b in new branch with characteristic specific mutations especially in T140A in antigenic site A and R72S in the receptor binding site when comparing with A/duck/Egypt/F446/2017 with low A.A identity percent with vaccinal strains (H5N1 and H5N2) reach to 91.9-94% and 84.6% respectively. The HA gene of AIV (H9N2) were belong to A/quail/Hong Kong/G1/97-like virus clustered with group B with specific mutation (212I) that may be effect on human transmission of the virus. The HVRs of S1 gene of IBV cluster to GI23 (Egy Var I) clad with multiple mutation in HVR1, HVR2 when comparing with IBV/CU/4/2014 and low identity percent (68.3%-78.8%) with vaccine strains (H120, M41, 4/91). In conclusion, the respiratory disease continues circulate and rapidly evolved in Egypt during 2020.